Explosive



Patented Sept. 22, 1936 PATENT OFFICE EXPLOSIVE Willard de G. Crater,Newark, Del, assignor. to

Hercules Powder Company, Wilmingto n, DeL,

a corporation of melaware NoDrawing. Application April 10, 1934, SerialThis invention relates to an explosive and method for its production.

The; explosive in accordance with this invention is characterized, moreparticularly, by the fact that it is a porous, granular, free-flowingmaterial, substantially free from any solvent and of a colloidal naturecomprising an explosive salt in crystalline form intimately mixed withand surrounded by a colloided nitrocarbohydrate.

The method in accordance with this invention more particularly involvesadmixing an explosive salt and a nitrated carbohydrate together with asolvent for the nitrated carbohydrate which is normally substantiallynon-solvent for the explosive salt, with the formation of a gel andfinally drying the gel by removal of the solvent therefrom.

The carrying out of the method in accordance with this invention and theproduction of the product in accordance herewith appears to depend uponthe peculiar phenomenon that solvents capable ofdissolving nitratedcarbohydrates, but which are normally substantially non-solvent forexplosive salts are in the form of a nitrated carbohydrate solutioncapable of enabling the formation of a gel between explosive salts andnitrated carbohydrates.

In proceeding to carry out the method in accordance with this inventionfor production of the product in accordance therewith any suitablenitrated carbohydrate may be used. As illustrative, for example,nitrated starch, which may be ordinary nitrated starch or which maypreferably be nitrated flaked starch, which is preferable due to moreuniform nitration obtainable on nitrating flaked starch, nitratedcellulose, as, for example, nitrated cotton or other nitrated cellulosemaybe used. Additional nitrated compounds such as, for example, nitratedinulin, may be used and it will be understood that in connection withthe following description of this invention and the claims appendedhereto, for example, nitrated inulin and other operable nitratedcompounds are to be regarded as equivalents for nitrated carbohydrates,such as nitrated starch and nitrated cotton.

, In carrying out the method in accordance with this invention for theproduction of the product contemplated, any of the well known explosivesalts may be used. Thus, for example, ammonium nitrate, ammoniumperchlorate, potassium perchlorate, potassium chlorate, sodium chlorate,etc., may be used and it will be also understood that in the followingdescription of this invention and in the claims appended hereto it scontemused. For illustration, for example, methanol, 10

acetone, ethyl acetate, etc., or mixtures thereof, may be used.

In the practical adaptation of the method in accordance with thisinvention. for example, the

explosive salt and nitrated carbohydrate are ad- 16 mixed with a solventto produce a gel which is thoroughly admixed and broken up and thendried, as, for example, by the evaporation of the solvent, leaving thefinished explosive in ac cordance with this invention, which may be usedas such or which may be admixed with various ingredients of explosives,as, for example, carbonaceous material, as wood meal, balsa wood, ivorynut meal, or the like, other explosives, as, for example, nitrolactose,nitromannitol, TNT, DNT, or the like, or with oxidizing agents, as, forexample, ferrosilicon, sodium nitrate, etc. Likewise, if desired, inorder to sensitize the explosive nitroglycerin in relatively smallquantity may be used.

In proceeding, any desired practice may be followed. However, it willgenerally be found desirable to add a quantity of the explosive salt tothe solvent and then add a part of the nitrated carbohydrate whilestirring the solution, then add more explosive salt and then morenitrated carbohydrate, until the desired amount of nitrated carbohydratehas been added, with finally the addition of the balance of explosivesalt. The whole is stirred and the gel which will form, broken up. Theconsistency of the gel will depend upon the ainount of solvent relativeto nitrated carbohydrate and explosive salt. The gel is finally dried byelimination of solvent. Varlous modifications of the practice may, ofcourse, be made. Thus, for example, the entire amount of explosive saltcan be added to the solvent and then the entire amount of nitratedcarbohydrate added, or the order of addition may be reversed, that is,the nitrated carbohydrate may be added to the solvent first, either intotal quantity or in part, followed by addition of the explosive salt,in total quantity or in part. Generally speaking, however, the additionof the explosive salt and nitrated carbohydrate to the solvent insuccessive portions will be preferred.

The method in accordance with this invention will, as will be obvious,be capable of being carried out in any suitable form of apparatus.However, it will be found convenient to use a mixer of the conventionaltype used for mixing gelatin dynamite or smokeless powder and the mixerwill be preferably of the jacketed type.

Satisfactory gels for the ultimate production of explosive in accordancewith this invention by drying out of the solvent may be produced on theformulae shown in the following table: titatiztli -t 2 a in a 2 53 aMethanol per 50.

gms ccl5 i5 15 15 20 2o 20 as The explosive in accordance with thisinvention will be found to be somewhat hygroscopic, but to have amoisture pick-up less than that of ammonium nitrate. Thus, for example,by exposure of a sample of the explosive at 20 C. in an atmosphere of90% humidity, ammonium nitrate will be practically in solution after 96hours, whereas the explosive in accordance with this invention will not'show any free solution until after a minimum of about 350 hoursexposure to such an atmosphere.

The explosive'will have a very high water resistance as compared withthat of ammonium nitrate and will show a pendulum friction testindicating relative insensitivity of the explosive and consequent safetyin handling. same time, the explosive may be readily detonated with anordinary blasting cap and will show good ballistic mortar test.

Generally speaking, the proportions of nitrated carbohydrate and ofammonium nitrate may be widely varied. As illustrative, but in no waylimiting, for example, the nitrated carbohydrate may vary within therange 5-20%, while the ammonium nitrate may vary within the range95-80%.

As illustrative of the use of solvent other than methanol, for example,a satisfactory explosive in accordance with the method of this inventionmay be made up on the following formula:

Ammonium nitrate 90% 90% Nitrostarch flakes 10% 10% Ethyl acetate-cc/50gms 20 cc. Acetone-cc/50 gms 20 cc.

As illustrative of an explosive in accordance with this inventionprepared in accordance with the method of this invention, for example, asatisfactory explosive may be made up on the following formula:

Nitrostarch flakes 10% 10% Ammonium perchlorate 90 Potassium chlorate 90Methyl alc. /50 gms 20 15 At the corporation of such additionalingredients, or, if desired, the additional ingredients may be mixedwith the explosive in accordance with this invention after drying. Astypical of explosive mixtures including various ingredients in additionto the explosive, for example, various mixtures as shown in thefollowing tables may be made.

As illustrative of the preparation of explosives in accordance with thisinvention using, for example, nitrocotton or nitrated inulin. indicatedas equivalent for nitrated starch, for example, an explosive may be madeon the formula shown in the following table:

Table D Nitrated inulin 107 Nitrocot f A nlh'ntn 95 90 Methyl alc. cc/50gms Further, if desired, various waxes or wax-like substances may beincluded in the explosive in accordance with this invention, as, forexample, paraflin, stearic acid, zinc stearate, etc. A satisfactoryexplosive in accordance with this invention may be prepared inaccordance with the following formula:

Table E Nitrostarch flakes Ammonium nitrate Paraflin Stearic Zinc steal-It will be understood that in preparing an explosive in accordance withthe method involving this invention, it will not be necessary to use thenitrated carbohydrate in a dry condition. Thus, for example, wetnitrated starch or nitrated cotton dehydrated with alcohol may be usedwet with alcohol directly without drying. This is believed to be adistinct advantage in that it will be unnecessary to dry and the dusthazard will be eliminated. Also, the use of wet nitrated carbohydrateeliminates the explosive hazard, since, for example, alcohol-wetnitrated starch cannot be detonated even with a standard blasting cap.

It will be understood that the various description and formulae of themethod embodying this invention and of the explosives in accordancetherewith are given by way of illustration only and are not to beconsidered as limiting, since it will-be understood that the inventionbroadly involves from the method standpoint the formation of a gel withthe use of an explosive salt and a nitrated carbohydrate or equivalentlyof nitrated inulin and the drying of the gel, the gel being broken up bystirring or in the admixing of .the ingredients. The explosive, as willbe understood, from the broad standpoint comprises the dried gelproduced by the method.

Further, it will be understood that this invention contemplates theincorporation in the gel of various ingredients other than the nitratedcarbohydrate and explosive salt, as indicated, or other suitableingredients not specifically mentioned. It will also be understood thatthe explosive in accordance with this invention will be used as such orwith such ingredients as may be incorporated therewithin its productionor in admixture with other ingredients adapted for the production of anexplosive of desired characteristics, as, for example, oxygen balance,sensitiveness, rate, free flowing, etc.

What I claim and desire to protect by Letters Patent is:

1. The method of producing a granular, freeflowing detonating explosivewhich includes forming,a gel including a crystalline explosive salt insolution and a non-crystalline nitrated carbohydrate and drying the gel.

2. The method of producing a granular, freefiowing detonating explosivewhich includes admixing a non-crystalline nitrated carbohydrate, acrystalline explosive salt in solution and a solvent for the formationof a gel and eliminating the solvent. 1

3. The method of producing a granular, freeflowing detonating explosivewhich includes admixing a non-crystalline nitrated carbohydrate and acrystalline explosive salt in solution in a solvent for the nitratedcarbohydrate which is normally substantially a non-solvent for theexplosive salt for the formation of a gel and drying the gel.

4. The method of producing a granular, freefiowing detonating explosivewhich includes forming a gel including nitrated starch and a crystallineexplosive salt in solution and drying the gel.

5. The method of producing a granular, freefiowing detonating explosivewhich includes forming a gel including nitrated starch and ammoniumnitrate in solution and drying the gel.

6. The method of producing a granular, freeflowing detonatingexplosivewhich includes forming a gel including nitrated cellulose and anexplosive salt in solution and drying the gel.

'7. A granular, free-flowing detonating explosive including a dried gelcontaining a non-crystalline nitrated carbohydrate and a crystallineexplosive salt.

8. A granular, free-flowing detonating explosive including an explosivesalt in crystalline form, the crystals of which are substantiallyencased and bound together by a dry colloided non-crystalline nitratedcarbohydrate.

9. A granular, free-flowing detonating explosive including a dried gelcontaining a non-crystalline nitrated carbohydrate and a crystallineexplosive salt and another explosive.

10. A granular, free-flowing detonating explosive including a dried gelcontaining ammonium nitrate and colloided nitrated starch.

11. A granular, free-flowing detonating explosive including an explosivesalt and colloided nitrocellulose.

12. The method of producing an explosive which includes forming a gelincluding a crystalline explosive salt in solution, a wax and anon-crystalline, nitrated carbohydrate and drying the gel.

13. A granular, free-flowing, detonating explosive including a dried gelcontaining a noncrystalline, nitrated carbohydrate in amount withinabout the range 5-20% and a crystalline explosive salt in amount withinabout the range 95-80%.

14. A granular, free-flowing, detonating explo sive including a driedgel containing colloided,

nitrated starch in amount within about the range WILLARD DE C. CRATER.

